A dramatic installation of falling rain — which visitors walk through without getting wet — has become the most popular attraction in Barbican history, with 12-hour queues to get in.

The Rain Room in the Barbican’s Curve Gallery stayed open until 1am on Saturday and finally closed at midnight yesterday after huge public interest led organisers to extend opening hours. In five months, more than 77,000 people have entered the room, where sensors detect the presence of visitors and respond by stopping the water falling to keep them dry.

The final pair, Sammy Ho and David Lam, both 25, stood in line for eight hours and said they had “never waited so long” to see art.Ms Ho, from Highgate, said: “We heard about it from friends and they said it was amazing. This was our last chance. We waited hours to get in.” Mr Lam, from East Ham, said: “The big attraction is that you are not passive, you are in it. It’s quite strange to think we are the last to see it.” Kelly Paul, 29, of Poplar, queued for 12 hours with mother Dorothy, 50. “I waited at H&M when Jimmy Choo was launching a new line, so I thought I’d give it a go for a more cultural cause,” Ms Paul said.

Rebecca Long, 19, left Manchester at 4am to see it and said: “I’d do it again if I had the choice.” Sir Nicholas Kenyon, the Barbican’s managing director, said the “elemental idea that you can stop the rain” had caught the public imagination and there had been queues since it opened on October 4. “We have been overwhelmed by the enthusiasm from so many diverse audiences.”

The work makes use of 2,000 litres of water. It is nominated for the Design Museum’s Designs of the Year awards. It was developed by Hannes Koch, Florian Ortkrass and Stuart Wood, who met at the Royal College of Art and work as rAndom International.